Preparation of divinyl benzene products



Patented June 12, 1945 PREPARATION OF DIVINYL BENZENE. PRODUCTS GaetanoF. D Alelio, Pittsfield, Mass., assignor to General Electric Company, a.corporation of New York No Drawing. Application June 23, 1942,

Serial No. 448,157

2 Claims.

This invention relates to the preparation of synthetic resincompositions and more particularly to the preparation ofheat-convertible, soluble, fusible polymers of divinyl benzene.

It is known that polymerization'of compounds possessing more than oneterminal grouping, providing the system is not conjugated, results inthe formation 01 9. cross-linked, insoluble, infusible polymer. Examplesof such comcommercial use a product heretofore inapplicable.

The process by which a soluble, fusible partial polymer of divinylbenzene may be isolated from a dialkyl benzene, having at least twocarbon atoms in each alkyl grouping, comprises polymer izing thesolution of divinyl benzene in a dialkyl benzene in the presence of bothcarbon tetrachloride, which acts as an inhibitor, and a catalyst ofpolymerization for a time less than that re-- quired to cause separationof the. polymer. The dissolved partial polymer is then precipitated bythe addition of a non-solvent or by evaporation of the volatileconstituents. Present production of divinyl benzene (monomer) is carriedout in such a manner that the resulting product is an inseparablemixture of about 20-30% divinyl benzene-in diethyl benzene. The presentinvention is of special interest because it utilizes this inseparablemixture for which there has been no use until the present time.

Extensive experiments carried out on the polymerization of eivliyibenzene m a. dialkyl benzene indicate that an insoluble, infusible resinis obtained as a 'gel when ordinary polymerization methods are employed.This gel formation or precipitation takes place in a very short time, e.g., 15-20 minutes. The extreme sensitivity of this resin precludes itsuse in industrial applications. By means of this invention I may causethe polymer to be formed at a much slower rate, thus providing a greaterpermissible deviation from any calculated time required to give amaximum yield of partial polymer. As seen in the following examples,whereas the divinyl' benzene solution alone gelled in about 10 minuteswhen it was polymerized with 0.50 part benzoyl peroxide, when carbontetrachloride was employed the solution had not yet gelled at the end of120 minutes. Furthermore, a sodium fusion test as well as a flame teston the purified polymer showed that some carbon tetrachloride hadco-reacted or polymerized with the divinyl benzene. This was entirelyunexpected and unpredictable.

The actual polymerization of the divinyl benzene from its solution in adialkyl benzene is carried out as previously indicated in the presenceof a catalyst. Any suitable method may be employed. For example, themixture may be activated by light having wave lengths of the order ofultra-violet radiations. However, I prefer to cause polymerization underthe influence of external heat in the presence of a catalyst for aperiod substantially less than that required to cause gellation of thesolution. For purposes of economy. and convenience I prefer to usereflux temperature and atmospheric pressure, although other elevatedtemperatures and pressures, ranging from subatmospheric tosuperatmospheric pressure, may be used. The partial polymer of divinylbenzene may be precipitated from the dialkyl benzene by the addition ofsome non-solvent, e. g., methyl alcohol, ethyl alcohol, glycol, etc.

For polymerization catalysts in the polymerization of divinyl benzene Imay use ozone, ozonides, inorganic super-oxides such as barium peroxide,sodium peroxide, etc., aliphatic acyl peroxides, e. g, acetyl peroxide,lauryl peroxide, stearyl peroxide, etc., peroxides of the aromatic acidseries, e. g., benzoyl peroxide, etc., ketone peroxides, e. g., acetoneperoxide, triacetone peroxide, alkyl derivatives of hydrogen peroxide,e. g., ethyl hydrogen peroxide, diethyl peroxide, etc., mixed organicperoxides, e. g., acetyl benzoyl peroxide, etc.,

various per compoundssuch as perborates, persulfates, perchlorates,etc., aluminum salts such as the halides, e. g., aluminum chloride,organic and inorganic acids such as methacrylic, hydrofluoric, etc.,metal compounds of the unsaturated acids as, for instance, cobalt andmanganese resinates, linoleates, maleates, etc., hydrogen peroxide, etc.However, benzoyl peroxide is a preferred catalyst. Any suitable amountof catalyst may be used but, in general, the catalyst concentration willbe within the range of 0.1-2.0% by weight of divinyl benzene.

In order that those skilled in the art may better understand thisinvention the following examples are given in which all parts are byweight.

Example 1 Parts by weight Divinyl benzene (106 parts of 23% soln. in

diethyl benzene) 24.4 Benzoyl peroxide 0.25

The above ingredients were refluxed for 17 minutes. At this point theresin gelled. With 0.5 part benzoyl peroxide the solution gelled in ashorter time, that is, in the order of minutes.

Example 2 Parts by weight Divinyl benzene (212 parts of 23% soln. indiethyl benzene) 50 Carbon tetrachloride 50 Benzoyl peroxide 1 The aboveingredients were refluxed for a period of 2 hours. The -thickenedsolution was now poured into methanol and precipitated. The partialpolymer was thoroughly triturated and dried and ground, yielding aneasily fusible polymer at elevated temperatures, e.g., 140 C.

The above ingredients were refluxed 100 minutes and then poured intomethanol. The precipitate was thoroughly triturated under meth- Example4 l Parts by Weight Divinyl benzene (108 parts of 23% soln. in

diethyl benzene) 25 Diallyl phthalate 2e Carbon tetrachloride 50 Benzoylperoxide 0.5

The above ingredients were refluxed 100 minutes and poured intomethanol. The precipitate was thoroughly triturated under methanol,dried and ground to a fine powder. The yield was 24 parts. The partialcopolymer obtained was fusible on a hot plate at C. and soluble intoluene and styrene.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. The process which comprises reacting under heat a mixture consistingof a solution of 20-30% of divinyl benzene in diethyl benzene and carbontetrachloride, until a fusible, heat-convertible, partial polymer ofco-reacted divinyl benzene and carbon tetrachloride is formed, andisolating the partial polymer.

2. The solid, fusible,- heat-convertible, partial polymer of divinylbenzene and carbon tetrachloride produced in accordance with the'processof claim 1.

GAE'IANO F. DALELIO.

